Octane Report

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Transcript of Octane Report



    September 2000



    TEL 03 9787 4793FAX 03 9770 1699

    E-mail: seddon@ozemail.com.au

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    Duncan Seddon & Associates has been retained by Environment Australia to provide aliterature survey and analysis of octane enhancers that may be used in Australia and help thenation to implement better fuel quality standards.

    The report has been prepared for the sole benefit of Environment Australia. Any third partyin the possession of the report may not rely upon its conclusions without the written consentof Duncan Seddon & Associates.

    Duncan Seddon & Associates conducted this analysis and prepared this report utilisingreasonable care and skill in applying methods of analysis consistent with normal industrypractice. All results are based on information available at the time of the study. Changes infactors upon which the study is based could affect the results. There is no implied warrantyor merchantability or fitness for a particular purpose shall apply.


    Duncan Seddon & Associates expresses its sincere thanks to contributions from Dr. JohnHarris of RMIT for his assistance and analysis of the blending of oxygenate additives andgasoline.

    I would also like to thank Professor Jorma Ahokas and Peter Jackson of RMIT for usefulcommentary on the toxicity of additives and for providing a reference to NOHSC data.

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    The move to harmonise Australian fuel standards with those of Europe willhave a profound effect on the manufacture and supply of petrol. Amongst otherfactors, harmonisation requires an increase in motor octane. This is the subjectof this Review.

    As well as increasing octane, harmonisation will require limits to be placed onthe levels of aromatics and olefines in the petrol. These components have anaturally high octane and the new limits will make the manufacture of high-octane petrol more difficult. Whilst this can be achieved, it will only be doneso at an increased cost to the motorist and an increased cost to the environment.

    In order to ameliorate these costs, octane-enhancing additives may prove usefulto Australian refiners and importers. The availability, cost and environmentalimpact of these additives are reviewed.

    We are concerned with the production of petrol, which has no other use than asa fuel for transport. Petrol comprises a mixture of many thousands of differenthydrocarbon compounds plus additives that may contain other elements. Veryfew are non-toxic or unhazardous in some way or other. Although used in largequantities by the motorist, the general public rarely comes into contact withpetrol. It is always confined to sealed vessels, and modern-filling techniquesminimises fugitive emissions and splashes.

    Like the components of petrol, each of the octane-enhancing additives presentenvironmental and health issues. All of the problems are solvable within theboundaries of fuel production, storage, transport and distribution.

    Fuel harmonisation is occurring across the world. Whilst the primary aim is tofacilitate the introduction of better emission standards for vehicles, there will beanother effect, namely an increase in trade of fuels as opposed to basestocksand refinery intermediates.

    Because fuels will be produced to similar standards across a range of countries(eg South Asia), there will be an opportunity for refiners to benefit fromeconomies of scale and supply several markets with petrol. This will serve tobenefit the motorist by holding down price rises that would otherwise occur asa result of the increased costs of production of the better quality fuel.

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    Although there will be opportunities for the larger and more modern Australianrefineries, the increased cost of producing the higher quality fuels may createdifficulties for the smaller and older refineries. Market share currently suppliedby the latter refineries may be lost to interstate refineries and imports.

    Because of the large volume use of petrol, and to minimise shipping costs, it isshipped in relatively large vessels. To permit effective trade and preventshortages, we have to guard against using Australian fuel standards as a meansof unfairly discriminating against imported product.

    The danger is the tendency to ban specific petrol components as a reaction toadverse media coverage or to pacify local political pressure. Obviously localbans of specific components is contrary to fuel harmonisation.

    A specific case in point is the ether additive MTBE. This is the most widelyused octane-enhancing additive, but is currently under suspicion in the US as acontaminant of water supplies. Because of the contamination of vessels,banning MTBE (and similar ethers) could effectively present a barrier toimporting lower cost petrol.

    Further, banning ethers (or any other additive) would require extensive testingof product. Because of the scale of import, refusal of entry of a contaminatedvessel, would result in disruptions to the local petrol supply chain, inevitablyincreased prices for the motorist, and potentially shortages and rationing.

    Taking all of these points into consideration, and aiming to achieve theoptimum outcome for the motorist, refiner, importer and the environment, thedirection of the recommendations is to facilitate maximum flexibility in thesupply of petrol to the proposed new, higher-octane petrol standards.

    Review Findings

    It is technically feasible for Australia to adopt Euro-3 petrol standards withoutresorting to octane enhancers. However, this will constrain the industry toproducing petrol high in aromatics.

    Mass production of high octane 98 RON and Euro-4 fuel will probably requireoctane enhancers.

    Suitable octane enhancers are alcohols, ethers and organometallics such as theadditive MMT.

  • vOf the alcohols, methanol is to be avoided. Ethanol is the alcohol of principalinterest. It is used in petrol in Australia and elsewhere. Ethanol can beproduced from biomass, but to remain competitive would require a subsidy -ethanol is currently free of excise.

    However, there are serious issues with the use of ethanol, which remain to beaddressed. These include air toxicity and water contamination. It is highlylikely that it will be difficult, if not impossible, for ethanol - petrol blends tomeet Euro-3 specifications from the standpoint of summer RVP (60 kPa limit).Waiving this limit for ethanol would undermine the reasoning for a low RVPvalue in Euro-3 and Euro-4.

    The use of higher alcohols (propanols, butanols) will be constrained by supplybut may be able to make an occasional contribution in selected instances.

    Of the ethers, MTBE is the preferred oxygenate of world oil industry. It iswidely used in Europe, the USA and the Far East. It is not currently used inAustralia.

    The controversy surrounding the use of MTBE is a consequence of the failureto properly control petrol transport and storage. All oxygenates (includingethanol) are likely to suffer a similar level of concern if they were widely used.

    The MTBE controversy may lead to the phase out of MTBE in the USA. Thisis likely to severely disrupt world markets for oxygenates and petrol feedstocks.It will cause a major worldwide reappraisal of the approach to octane.

    It is doubtful if Europe could adopt the new standards (Euro-3 and Euro-4)without the use of MTBE.

    Other ethers (TAME, ETBE, DIPE) are likely to be useful in occasionalcircumstances. Their use is likely to be constrained by supply. Their use islikely to be marred by the MTBE controversy.

    The use of the manganese additive MMT is highly controversial but hasgrowing acceptance in the refining industry. MMT may be useful in producinglead replacement petrol and to achieve the lower Euro-4 aromatics level.

    Optimum results may be obtained by using a mixture of additives so as toameliorate the deficiencies of each of the additives.

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    1. MTBE is the preferred octane enhancer of the world oil industry andwould be suitable for use in Australia. In order to ameliorate concernswith groundwater contamination, a national audit on the status of gasolinetransport (pipelines) and storage should be conducted with the object ofidentifying issues that would lead to pollution of water supplies by anygasoline component.

    2. Prima facie the use of ethanol is incompatible with proposed standards

    with respect to oxygen content and RVP at the commonly used 10% level.Waivers specifically for ethanol in these areas are not in line with the aim ofthe standards. Nevertheless, we recognise the social desire to see ethanolincluded in the Australian gasoline pool. The use of ethanol in futureAustralian gasoline pool should be subject to further analysis, particularlydefining how the required RVP from ethanol blends can be met usingAustralian basestocks.

    3. In order to maximise the flexibility for refiners or importers to providehigh octane gasoline, it is possible that ETBE and TAME could be used,once these chemicals have been notified by potential manufacturers andimporters to NICNAS and assessment certificates have been issued. ETBEand TAME are not currently listed on AICS.

    4. The widespread introduction of 98 octane fuel would require a substantialreview of octane production in Australia, implying a major overhaul ofrefinery operations. It is not clear if 98 octane will result in a net globalemissions improvement. Until this is clarified by additional work, thewidespread introduction of 98 octane gasoline should not be en